I believe that x=4 would be the answer
Answer:
and 
Step-by-step explanation:
If two equations are given, we can solve one of the equation in terms of single variable and put it in the other equation which will further give the value of x and y.
For the given equations:
Equation:1
Equation:2
Solving equation multiply equation 2 with 4 on both the sides
Equation 3
Subtracting Equation:3 from Equation:1

Putting value of 'y' in Equation:2 which will give the value of x

Answer:
x=80
Step-by-step explanation:
First of all, you must find the length of the side to add with 36 to equal 100. This would give you 64. So once you do that, you can do pythagorean theorem to find the length of x. This would give you 64^2 + 48^2 = x^2. Once you have this equation, you square your terms to get; 4,096 + 2,304 = x^2. After you add them you will now have 6,400 = x^2. Once you have this, you will need to do the square root of both sides of the equation; sqrt(6400) = x. This gives you x = 80.
Hope this helps!
Brainliest?
3x+4x+5x=90
combine like terms
12x = 90
divide by 12
x = 7.5
sides: 3(7.5) ,4(7.5) ,5(7.5)
22.5, 30, 37.5